O
OCC - Office of the Comptroller of the Currency (oversight of nationally chartered banks)
OCR - Office for Civil Rights (division within the Department of Health and Human Services given responsibility for enforcement of the Health Insurance Portability and Accountability Act (HIPAA) Privacy and Security Rules as a result of legislative changes created by the Health Information Technology for Economic and Clinical Health (HITECH) Act in 2009 - the Office for Civil Rights should not be confused with the Civil Rights Division of the Department of Justice, created to enforce the Civil Rights Act of 1964.)
ODC - Office of/for Domestic Preparedness (division of the Department of Homeland Security (DHS))
ODNI - Office of the Director of National Intelligence (FISMA/intelligence agencies)
OECD - Organization for Economic Cooperation and Development (international organization focusing on economic development)
OG - Official Gazette for Trademarks (intellectual property)
OHS - Office of Homeland Security (Executive Branch - established by presidential Executive Order)
OMB - Office of Management and Budget (oversight of federal agencies)
OPPA - Online Privacy Protection Act of 2003 (California privacy law)
OSH Act - Occupational Safety and Health Act (facility safety - toxic, hazardous chemicals)
OSHA - Occupational Safety and Health Administration (workplace safety oversight)
OTS - Office of Thrift Supervision (federal agency with oversight of thrift institutions - abolished in 2011 by Dodd-Frank Act)